External fixation systems are used to stabilize fractured bones or hold bones after corrective surgery. They are usually made up of structural members held together by clamps, all assembled by the surgeon during surgery. The clamps are placed on bone pins and are attached to bars, creating a frame to hold the bones in particular relationships. Typically, the external fixation frame is assembled in the configuration the surgeon desires, then the fracture is reduced and the clamps are tightened.
Some external fixation systems include two-part clamping devices for gripping the structural members. These clamping devices typically include two clamps formed of jaw sets that swivel about a post that runs through both clamps. These clamps allow rotation about the external fixation element, or rotation about the roll axis of each clamp. They also include rotation about the post component, or rotation about the yaw axis of the clamp. One known clamping device includes a ball joint that allows additional rotation about a pitch axis. This device allows the jaw to roll, pitch and yaw on the ball joint while the jaw can also roll about the external fixation element, giving it redundant degrees of freedom. Friction maintains the orientation of the jaw set relative to whatever the jaw set is mounted upon. Another known clamping device includes concave surfaces that guide additional rotation about the pitch axis. Because the jaw set of this clamping device angles relative to the post, the clamping load is reduced to the cosine of the pitch angle. This requires that the designer limit the amount of angulation appropriately.
The present disclosure addresses one or more of the problems found in the prior art.